Merge pull request #888 from BCDA-APS/887-apsu-subnet-check

check proper subnet for APSU beamlines

CHANGES.rst

@@ -36,6 +36,7 @@ New Features
 * Add (ophyd) device support for
   * DG-645 digital delay/pulse generator
   * Measurement Computing USB CTR08 High-Speed Counter/Timer
+* Add subnet check for APSU beamlines.
 * New lineup2() plan can be used in console, notebooks, and queueserver.
 
 1.6.17

apstools/utils/__init__.py

@@ -2,6 +2,8 @@
 
 from .aps_data_management import dm_setup
 
+from .apsu_controls_subnet import warn_if_not_aps_controls_subnet
+
 from .catalog import copy_filtered_catalog
 from .catalog import findCatalogsInNamespace
 from .catalog import getCatalog

apstools/utils/apsu_controls_subnet.py

@@ -0,0 +1,65 @@
+"""
+APS-U controls are on private subnets.  Check and advise as applicable.
+
+.. autosummary::
+
+    ~warn_if_not_aps_controls_subnet
+"""
+
+APSU_CONTROLS_SUBNET = "10.54."
+APSU_XRAY_SUBNET = ".xray.aps.anl.gov"
+
+
+def warn_if_not_aps_controls_subnet():
+    """
+    APS-U controls are on private subnets.  Check and advise as applicable.
+
+    Call this function early in the startup procedure. It could explain easily
+    the reason for subsequent EPICS PV connection failures.
+
+    For workstations on subnets that do not match the criteria, this function
+    should not post any warnings.
+    """
+
+    import socket
+    import warnings
+
+    host_name = socket.gethostname()
+    if host_name.endswith(APSU_XRAY_SUBNET):
+        host_ip_addr = socket.gethostbyname(host_name)
+        if not host_ip_addr.startswith(APSU_CONTROLS_SUBNET):
+            warnings.warn(
+                f"Your APS workstation ({host_name}) has IP {host_ip_addr!r}."
+                "  If you experience EPICS connection timeouts,"
+                " consider switching to a workstation on the controls subnet"
+                f" which has an IP starting with {APSU_CONTROLS_SUBNET!r}"
+            )
+
+
+def warn_if_not_aps_controls_subnet():
+    """
+    APS-U controls are on private subnets.  Check and advise as applicable.
+
+    Call this function early in the startup procedure. It could explain easily
+    the reason for subsequent EPICS PV connection failures.
+
+    For workstations on subnets that do not match the criteria, this function
+    should not post any warnings.
+    """
+
+    import socket
+    import warnings
+
+    xray_subnet = ".xray.aps.anl.gov"
+    controls_subnet = "10.54."
+
+    host_name = socket.gethostname()
+    if host_name.endswith(xray_subnet):
+        host_ip_addr = socket.gethostbyname(host_name)
+        if not host_ip_addr.startswith(controls_subnet):
+            warnings.warn(
+                f"Your APS workstation ({host_name}) has IP {host_ip_addr!r}."
+                "  If you experience EPICS connection timeouts,"
+                " consider switching to a workstation on the controls subnet"
+                f" which has an IP starting with {controls_subnet!r}"
+            )

apstools/utils/tests/test_subnet_warning.py

@@ -0,0 +1,21 @@
+import socket
+from contextlib import nullcontext as does_not_raise
+
+import pytest
+
+from ..apsu_controls_subnet import APSU_CONTROLS_SUBNET
+from ..apsu_controls_subnet import APSU_XRAY_SUBNET
+from ..apsu_controls_subnet import warn_if_not_aps_controls_subnet
+
+
+def test_subnet_check():
+    host_name = socket.gethostname()
+    host_ip_addr = socket.gethostbyname(host_name)
+    # fmt: off
+    warns = (
+        host_name.endswith(APSU_XRAY_SUBNET)
+        and not host_ip_addr.startswith(APSU_CONTROLS_SUBNET)
+    )
+    # fmt: on
+    with pytest.raises(UserWarning) if warns else does_not_raise():
+        warn_if_not_aps_controls_subnet()

docs/source/api/_utils.rst

@@ -58,6 +58,7 @@ Other Utilities
 .. autosummary::
 
    ~apstools.utils.aps_data_management.dm_setup
+   ~apstools.utils.apsu_controls_subnet.warn_if_not_aps_controls_subnet
    ~apstools.utils.misc.cleanupText
    ~apstools.utils.misc.connect_pvlist
    ~apstools.utils.email.EmailNotifications
@@ -132,6 +133,9 @@ Submodules
 .. automodule:: apstools.utils.aps_data_management
     :members:
 
+.. automodule:: apstools.utils.apsu_controls_subnet
+    :members:
+
 .. automodule:: apstools.utils.catalog
     :members: